MP 1,1-5,1 No Response from Power Button

[michaelbirdart]

On my Mac Pro (early 2009) I was having trouble getting a couple of large files (on my non-boot drive) to delete this morning, so after a reasonable wait, I went to relaunch the Finder. The finder wouldn't restart, so I opened up the system panel, which gave me the apple menu and I chose to restart. It successfully started to prepare for restart, but then pinwheeled on the final turnover. Once I had determined that the files saving was finished, I went to hold down the power button to force the shut down and received no joy. Confused, I unplugged the machine. Once I replaced power, I went to power up and the power button is just as unresponsive as it was when I was trying to force the shut down. Obviously I don't think it's a mechanical issue at the power supply and while there might be issues with a hard drive (hard to rule out), I can't imagine it would prevent power up. Of course, I tried alternate power plugs with all peripherals disconnected. Same problem.

My thinking is that I have a dead logic board, but obviously I would love to find out there are other, less final prognoses possible. Any ideas?

 

[michaelbirdart]

One more detail I should add that is informing my thinking. I had to replace the power supply in this tower back in December. Ever since, the usb ports and headphone jack on the front next to the power button have been failing to work. I chalked it up to a re-connection problem, but obviously the power button has worked just fine. Only now is it showing any issues.

 

[Macschrauber]

you can remove the real time clock battery (the BR2032 near the PCIe Slot 1).

after plugging in mains the box should start. It's a failback behaviour for a dead battery.

also consider the technician source for shorting the power on pads near the diagnostic switch.

 

[michaelbirdart]

[reposted]

 

[michaelbirdart]

you can remove the real time clock battery (the BR2032 near the PCIe Slot 1).

after plugging in mains the box should start. It's a failback behaviour for a dead battery.

also consider the technician source for shorting the power on pads near the diagnostic switch.

Yep, started right up. THANK YOU!!!

I gather I should replace this battery, yeah? I don’t think I ever have before in the 12-13 years of operation.

 

[Macschrauber]

not really, check the voltage, everything below 3 Volts should mean that you need to replace it.

Double check the cabling between the Backplane and the Front Panel.

It is just a workaround about a non working power switch to diagnose.

 

[Macschrauber]

here is the jumpstart procedure for a regular startup of the box with connected rtc battery:

 

[michaelbirdart]

here is the jumpstart procedure for a regular startup of the box with connected rtc battery:

View attachment 2010877

Thank you. I'm going to take this in to a hardware tech this week to have these steps looked over. This is very helpful.